Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 November 2021 | 13(13): 20128–20129
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.7394.13.13.20128-20129
#7394 | Received 04 May 2021 | Final received
01 July 2021 | Finally accepted 02 October 2021
An unusual vocalization of Brown
Hawk-Owl Ninox scutulata
(Raffles, 1822) (Aves: Strigiformes: Strigidae) recorded from Kerala, India
Riju P. Nair 1 & Shine
Raj Tholkudiyil 2
1,2 Wildlife Biology department,
Kerala Forest Research Institute, Peechi, Kerala
680653, India..
1 rijupnair2009@gmail.com, 2 shineraj263@gmail.com
(corresponding author)
Editor: H. Byju, Coimbatore, Tamil Nadu, India. Date
of publication: 26 November 2021 (online & print)
Citation: Nair.R.P.
& S.R. Tholkudiyil (2021). An unusual vocalization of Brown
Hawk-Owl Ninox scutulata
(Raffles, 1822) (Aves: Strigiformes: Strigidae) recorded from Kerala, India. Journal of Threatened Taxa 13(13): 20128–20129. https://doi.org/10.11609/jott.7394.13.13.20128-20129
Copyright: © Nair & Tholkudiyil
2021. Creative Commons Attribution
4.0 International License. JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: None.
Competing interests: The authors
declare no competing interests.
Acknowledgements: We are grateful to Director, KFRI
for facilities provided. We wish to thank Dr E.A. Jayson, Dr S. Babu, Sathyan Meppayur, and Dr Zaibin for
the motivation and help extended for the identification and analysis. Special
thanks to Yadhu and Sumod
for rendering field support.
The distribution of the Brown
Hawk-Owl ranges from the Himalayan foothills of northern India to the
Western Ghats of southern India and in Sri Lanka (Ali & Ripley 1974; Grimmet et al. 1998). The species has a viable population
in most of the protected areas of Kerala located along the southern Western
Ghats, and its encounter rate is reported to be significantly higher in
mid-altitude and moist deciduous forest (Jayson & Sivaram
2009). On 08 May 2020, at 2235h, we heard a very distinct and unusual call in
the campus of Kerala Forest Research Institute (KFRI), Peechi,
Thrissur. The campus (10.526N & 76.350E) is located on a slope of a hill
ridge covered with a secondary moist deciduous forest patch near Peechi-Vazhani Wildlife Sanctuary. The call was of
one-minute duration comprising of five repetitive ‘kuh-hoo’
phrases. Since the call was unfamiliar we recorded the call using a mobile
phone.
After a gap of one month we heard
a very similar call on 10 July 2020 at 2310h,this time the call was intense and
more frequent than last time. We followed the call and to our surprise it was
found to be produced by a pair of Brown Hawk-Owls. Since then, we heard the
distinctive continuous calls of the species for the subsequent 15 days, mostly
after 2230 h and more frequently during 2315h to 2345h. We photographed the
vocalising bird on 11 July using a Sony DSC-HX400V camera (Image 1).
Spectrograms and measurements of
the recorded calls were made using Raven Pro v. 1.6. Each phrase in a call bout
comprised of about 8–11 notes (Image 2b) spanning about 0.5 seconds. The centre
frequency was c. 3kHz (Image 2b). The
recorded call has been deposited in the Xeno-canto
foundation (shineraj, XC643715 (Audio
1); shineraj, XC660215 (Audio
2))
The pair of Hawk-Owls were seen
in the area at multiple times roosting in a big, old tree (Grewia
tiliifolia), personal observation by the author
before the incident. The tree being old and because of its proximity to the
road it was removed on concerns of public safety. We suspect that the unusual
call from the owls happened as a result of the felling of the Grewia tiliifolia tree
which might have been their nesting site and the sudden loss of it may have
caused this unusual behaviour.
The studies which focussed on the
vocalization of Brown Hawk-Owl in India and other Oriental regions (Neelakantan 1979; Hutchinson et al. 2006; Babu & Jayson 2007; Jayson & Sivaram
2009; Rasmussen et al. 2012) and the information available in the public domain
such as eBird and xeno-canto
did not describe the peculiar vocalisation illustrated here which seems to be a
new addition to the existing recorded vocalisation of the species.
References
Ali, S. &
S.D. Ripley (1981). Handbook of the birds of India and Pakistan together with those of
Bangladesh, Nepal, Bhutan and Ceylon. Stone Curlews to Owls. 2nd Edition. Oxford
University Press, Delhi, i–xvi+327pp.
Babu, S. & E.A. Jayson (2007). Habitat use and response
behaviour of Brown hawkowl (Ninox
scutulata) to the conspecific broadcasted calls.
Abstract of 31st Annual Conference of Ethological Society of India,
Bangalore, 107pp.
Grimmet, R., C. Inskipp
& T. Inskipp (1998). Birds of the Indian Subcontinent. Oxford University Press, Delhi,
439pp.
Hutchinson,
R., J. Eaton & P. Benstead (2006). Observations of Cinnabar Hawk Owl
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description of a secondary vocalisation. Forktail
22: 120–121.
Jayson, E.A.
& M. Sivaram (2009). Ecology and behaviour of forest
owls in the Western Ghats and developing a habitat model for their
conservation. KFRI Research Report No. 343. Kerala Forest Research Institute, Peechi, 179pp.
Neelakantan, K.K. (1979). The voice of the juvenile Brown
Hawk-owl Ninox scutulata
(Rafles). Journal of the Bombay Natural History
Society 76: 363–364.
Rasmussen,
P.C., D.N.S. Allen, N.J. Collar, B. Demeulemeester,
R.O. Hutchinson, P.G.C. Jakosalem, R.S. Kennedy, F.R.
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Xeno-canto Foundation: shineraj,
XC643715. Accessible at www.xeno-canto.org/643715
Xeno-canto Foundation: shineraj,
XC660215. Accessible at www.xeno-canto.org/643715
Xeno-canto Foundation: https://www.xeno-canto.org/species/Ninox-scutulata